kern.c revision 161364 
1/*-
2 * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 * 3. Berkeley Software Design Inc's name may not be used to endorse or
13 *    promote products derived from this software without specific prior
14 *    written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 *      from BSDI kern.c,v 1.2 1998/11/25 22:38:27 don Exp
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: head/usr.sbin/rpc.lockd/kern.c 161364 2006-08-16 18:33:35Z thomas $");
33
34#include <sys/param.h>
35#include <sys/mount.h>
36#include <sys/queue.h>
37#include <sys/socket.h>
38#include <sys/stat.h>
39
40#include <netinet/in.h>
41#include <arpa/inet.h>
42
43#include <err.h>
44#include <errno.h>
45#include <fcntl.h>
46#include <paths.h>
47#include <pwd.h>
48#include <stdio.h>
49#include <stdlib.h>
50#include <string.h>
51#include <syslog.h>
52#include <unistd.h>
53#include <netdb.h>
54
55#include "nlm_prot.h"
56#include <nfs/rpcv2.h>
57#include <nfs/nfsproto.h>
58#include <nfsclient/nfs_lock.h>
59
60#include "lockd.h"
61#include "lockd_lock.h"
62#include <nfsclient/nfs.h>
63
64#define DAEMON_USERNAME	"daemon"
65
66/* Lock request owner. */
67typedef struct __owner {
68	pid_t	 pid;				/* Process ID. */
69	time_t	 tod;				/* Time-of-day. */
70} OWNER;
71static OWNER owner;
72
73static char hostname[MAXHOSTNAMELEN + 1];	/* Hostname. */
74static int devfd;
75
76static void	client_cleanup(void);
77static const char *from_addr(struct sockaddr *);
78int	lock_request(LOCKD_MSG *);
79static void	set_auth(CLIENT *cl, struct xucred *ucred);
80void	show(LOCKD_MSG *);
81int	test_request(LOCKD_MSG *);
82int	unlock_request(LOCKD_MSG *);
83
84static int
85nfslockdans(int vers, struct lockd_ans *ansp)
86{
87
88	ansp->la_vers = vers;
89	return (write(devfd, ansp, sizeof *ansp) <= 0);
90}
91
92/*
93 * will break because fifo needs to be repopened when EOF'd
94 */
95#define lockd_seteuid(uid)	seteuid(uid)
96
97#define d_calls (debug_level > 1)
98#define d_args (debug_level > 2)
99
100static const char *
101from_addr(saddr)
102	struct sockaddr *saddr;
103{
104	static char inet_buf[INET6_ADDRSTRLEN];
105
106	if (getnameinfo(saddr, saddr->sa_len, inet_buf, sizeof(inet_buf),
107			NULL, 0, NI_NUMERICHOST) == 0)
108		return inet_buf;
109	return "???";
110}
111
112void
113client_cleanup(void)
114{
115	(void)lockd_seteuid(0);
116	exit(-1);
117}
118
119/*
120 * client_request --
121 *	Loop around messages from the kernel, forwarding them off to
122 *	NLM servers.
123 */
124pid_t
125client_request(void)
126{
127	LOCKD_MSG msg;
128	int nr, ret;
129	pid_t child;
130	uid_t daemon_uid;
131	struct passwd *pw;
132
133	/* Open the dev . */
134	devfd = open(_PATH_DEV _PATH_NFSLCKDEV, O_RDWR | O_NONBLOCK);
135	if (devfd < 0) {
136		syslog(LOG_ERR, "open: %s: %m", _PATH_NFSLCKDEV);
137		goto err;
138	}
139
140	signal(SIGPIPE, SIG_IGN);
141
142	/*
143	 * Create a separate process, the client code is really a separate
144	 * daemon that shares a lot of code.
145	 */
146	switch (child = fork()) {
147	case -1:
148		err(1, "fork");
149	case 0:
150		setproctitle ("client");
151		break;
152	default:
153		setproctitle ("server");
154		return (child);
155	}
156
157	signal(SIGHUP, (sig_t)client_cleanup);
158	signal(SIGTERM, (sig_t)client_cleanup);
159
160	/* Setup. */
161	(void)time(&owner.tod);
162	owner.pid = getpid();
163	(void)gethostname(hostname, sizeof(hostname) - 1);
164
165	pw = getpwnam(DAEMON_USERNAME);
166	if (pw == NULL) {
167		syslog(LOG_ERR, "getpwnam: %s: %m", DAEMON_USERNAME);
168		goto err;
169	}
170	daemon_uid = pw->pw_uid;
171	/* drop our root priviledges */
172	(void)lockd_seteuid(daemon_uid);
173
174	for (;;) {
175		/* Read the fixed length message. */
176		if ((nr = read(devfd, &msg, sizeof(msg))) == sizeof(msg)) {
177			if (d_args)
178				show(&msg);
179
180			if (msg.lm_version != LOCKD_MSG_VERSION) {
181				syslog(LOG_ERR,
182				    "unknown msg type: %d", msg.lm_version);
183			}
184			/*
185			 * Send it to the NLM server and don't grant the lock
186			 * if we fail for any reason.
187			 */
188			switch (msg.lm_fl.l_type) {
189			case F_RDLCK:
190			case F_WRLCK:
191				if (msg.lm_getlk)
192					ret = test_request(&msg);
193				else
194					ret = lock_request(&msg);
195				break;
196			case F_UNLCK:
197				ret = unlock_request(&msg);
198				break;
199			default:
200				ret = 1;
201				syslog(LOG_ERR,
202				    "unknown lock type: %d", msg.lm_fl.l_type);
203				break;
204			}
205			if (ret) {
206				struct lockd_ans ans;
207
208				ans.la_msg_ident = msg.lm_msg_ident;
209				ans.la_errno = EHOSTUNREACH;
210
211				if (nfslockdans(LOCKD_ANS_VERSION, &ans)) {
212					syslog((errno == EPIPE ? LOG_INFO :
213						LOG_ERR), "process %lu: %m",
214						(u_long)msg.lm_msg_ident.pid);
215				}
216			}
217		} else if (nr == -1) {
218			if (errno != EAGAIN) {
219				syslog(LOG_ERR, "read: %s: %m", _PATH_NFSLCKDEV);
220				goto err;
221			}
222		} else if (nr != 0) {
223			syslog(LOG_ERR,
224			    "%s: discard %d bytes", _PATH_NFSLCKDEV, nr);
225		}
226	}
227
228	/* Reached only on error. */
229err:
230	(void)lockd_seteuid(0);
231	_exit (1);
232}
233
234void
235set_auth(cl, xucred)
236	CLIENT *cl;
237	struct xucred *xucred;
238{
239	int ngroups;
240
241	ngroups = xucred->cr_ngroups - 1;
242	if (ngroups > NGRPS)
243		ngroups = NGRPS;
244        if (cl->cl_auth != NULL)
245                cl->cl_auth->ah_ops->ah_destroy(cl->cl_auth);
246        cl->cl_auth = authunix_create(hostname,
247                        xucred->cr_uid,
248                        xucred->cr_groups[0],
249                        ngroups,
250                        &xucred->cr_groups[1]);
251}
252
253
254/*
255 * test_request --
256 *	Convert a lock LOCKD_MSG into an NLM request, and send it off.
257 */
258int
259test_request(LOCKD_MSG *msg)
260{
261	CLIENT *cli;
262	struct timeval timeout = {0, 0};	/* No timeout, no response. */
263	char dummy;
264
265	if (d_calls)
266		syslog(LOG_DEBUG, "test request: %s: %s to %s",
267		    msg->lm_nfsv3 ? "V4" : "V1/3",
268		    msg->lm_fl.l_type == F_WRLCK ? "write" : "read",
269		    from_addr((struct sockaddr *)&msg->lm_addr));
270
271	if (msg->lm_nfsv3) {
272		struct nlm4_testargs arg4;
273
274		arg4.cookie.n_bytes = (char *)&msg->lm_msg_ident;
275		arg4.cookie.n_len = sizeof(msg->lm_msg_ident);
276		arg4.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0;
277		arg4.alock.caller_name = hostname;
278		arg4.alock.fh.n_bytes = (char *)&msg->lm_fh;
279		arg4.alock.fh.n_len = msg->lm_fh_len;
280		arg4.alock.oh.n_bytes = (char *)&owner;
281		arg4.alock.oh.n_len = sizeof(owner);
282		arg4.alock.svid = msg->lm_msg_ident.pid;
283		arg4.alock.l_offset = msg->lm_fl.l_start;
284		arg4.alock.l_len = msg->lm_fl.l_len;
285
286		if ((cli = get_client(
287		    (struct sockaddr *)&msg->lm_addr,
288		    NLM_VERS4)) == NULL)
289			return (1);
290
291		set_auth(cli, &msg->lm_cred);
292		(void)clnt_call(cli, NLM_TEST_MSG,
293		    (xdrproc_t)xdr_nlm4_testargs, &arg4,
294		    (xdrproc_t)xdr_void, &dummy, timeout);
295	} else {
296		struct nlm_testargs arg;
297
298		arg.cookie.n_bytes = (char *)&msg->lm_msg_ident;
299		arg.cookie.n_len = sizeof(msg->lm_msg_ident);
300		arg.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0;
301		arg.alock.caller_name = hostname;
302		arg.alock.fh.n_bytes = (char *)&msg->lm_fh;
303		arg.alock.fh.n_len = msg->lm_fh_len;
304		arg.alock.oh.n_bytes = (char *)&owner;
305		arg.alock.oh.n_len = sizeof(owner);
306		arg.alock.svid = msg->lm_msg_ident.pid;
307		arg.alock.l_offset = msg->lm_fl.l_start;
308		arg.alock.l_len = msg->lm_fl.l_len;
309
310		if ((cli = get_client(
311		    (struct sockaddr *)&msg->lm_addr,
312		    NLM_VERS)) == NULL)
313			return (1);
314
315		set_auth(cli, &msg->lm_cred);
316		(void)clnt_call(cli, NLM_TEST_MSG,
317		    (xdrproc_t)xdr_nlm_testargs, &arg,
318		    (xdrproc_t)xdr_void, &dummy, timeout);
319	}
320	return (0);
321}
322
323/*
324 * lock_request --
325 *	Convert a lock LOCKD_MSG into an NLM request, and send it off.
326 */
327int
328lock_request(LOCKD_MSG *msg)
329{
330	CLIENT *cli;
331	struct nlm4_lockargs arg4;
332	struct nlm_lockargs arg;
333	struct timeval timeout = {0, 0};	/* No timeout, no response. */
334	char dummy;
335
336	if (d_calls)
337		syslog(LOG_DEBUG, "lock request: %s: %s to %s",
338		    msg->lm_nfsv3 ? "V4" : "V1/3",
339		    msg->lm_fl.l_type == F_WRLCK ? "write" : "read",
340		    from_addr((struct sockaddr *)&msg->lm_addr));
341
342	if (msg->lm_nfsv3) {
343		arg4.cookie.n_bytes = (char *)&msg->lm_msg_ident;
344		arg4.cookie.n_len = sizeof(msg->lm_msg_ident);
345		arg4.block = msg->lm_wait ? 1 : 0;
346		arg4.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0;
347		arg4.alock.caller_name = hostname;
348		arg4.alock.fh.n_bytes = (char *)&msg->lm_fh;
349		arg4.alock.fh.n_len = msg->lm_fh_len;
350		arg4.alock.oh.n_bytes = (char *)&owner;
351		arg4.alock.oh.n_len = sizeof(owner);
352		arg4.alock.svid = msg->lm_msg_ident.pid;
353		arg4.alock.l_offset = msg->lm_fl.l_start;
354		arg4.alock.l_len = msg->lm_fl.l_len;
355		arg4.reclaim = 0;
356		arg4.state = nsm_state;
357
358		if ((cli = get_client(
359		    (struct sockaddr *)&msg->lm_addr,
360		    NLM_VERS4)) == NULL)
361			return (1);
362
363		set_auth(cli, &msg->lm_cred);
364		(void)clnt_call(cli, NLM_LOCK_MSG,
365		    (xdrproc_t)xdr_nlm4_lockargs, &arg4,
366		    (xdrproc_t)xdr_void, &dummy, timeout);
367	} else {
368		arg.cookie.n_bytes = (char *)&msg->lm_msg_ident;
369		arg.cookie.n_len = sizeof(msg->lm_msg_ident);
370		arg.block = msg->lm_wait ? 1 : 0;
371		arg.exclusive = msg->lm_fl.l_type == F_WRLCK ? 1 : 0;
372		arg.alock.caller_name = hostname;
373		arg.alock.fh.n_bytes = (char *)&msg->lm_fh;
374		arg.alock.fh.n_len = msg->lm_fh_len;
375		arg.alock.oh.n_bytes = (char *)&owner;
376		arg.alock.oh.n_len = sizeof(owner);
377		arg.alock.svid = msg->lm_msg_ident.pid;
378		arg.alock.l_offset = msg->lm_fl.l_start;
379		arg.alock.l_len = msg->lm_fl.l_len;
380		arg.reclaim = 0;
381		arg.state = nsm_state;
382
383		if ((cli = get_client(
384		    (struct sockaddr *)&msg->lm_addr,
385		    NLM_VERS)) == NULL)
386			return (1);
387
388		set_auth(cli, &msg->lm_cred);
389		(void)clnt_call(cli, NLM_LOCK_MSG,
390		    (xdrproc_t)xdr_nlm_lockargs, &arg,
391		    (xdrproc_t)xdr_void, &dummy, timeout);
392	}
393	return (0);
394}
395
396/*
397 * unlock_request --
398 *	Convert an unlock LOCKD_MSG into an NLM request, and send it off.
399 */
400int
401unlock_request(LOCKD_MSG *msg)
402{
403	CLIENT *cli;
404	struct nlm4_unlockargs arg4;
405	struct nlm_unlockargs arg;
406	struct timeval timeout = {0, 0};	/* No timeout, no response. */
407	char dummy;
408
409	if (d_calls)
410		syslog(LOG_DEBUG, "unlock request: %s: to %s",
411		    msg->lm_nfsv3 ? "V4" : "V1/3",
412		    from_addr((struct sockaddr *)&msg->lm_addr));
413
414	if (msg->lm_nfsv3) {
415		arg4.cookie.n_bytes = (char *)&msg->lm_msg_ident;
416		arg4.cookie.n_len = sizeof(msg->lm_msg_ident);
417		arg4.alock.caller_name = hostname;
418		arg4.alock.fh.n_bytes = (char *)&msg->lm_fh;
419		arg4.alock.fh.n_len = msg->lm_fh_len;
420		arg4.alock.oh.n_bytes = (char *)&owner;
421		arg4.alock.oh.n_len = sizeof(owner);
422		arg4.alock.svid = msg->lm_msg_ident.pid;
423		arg4.alock.l_offset = msg->lm_fl.l_start;
424		arg4.alock.l_len = msg->lm_fl.l_len;
425
426		if ((cli = get_client(
427		    (struct sockaddr *)&msg->lm_addr,
428		    NLM_VERS4)) == NULL)
429			return (1);
430
431		set_auth(cli, &msg->lm_cred);
432		(void)clnt_call(cli, NLM_UNLOCK_MSG,
433		    (xdrproc_t)xdr_nlm4_unlockargs, &arg4,
434		    (xdrproc_t)xdr_void, &dummy, timeout);
435	} else {
436		arg.cookie.n_bytes = (char *)&msg->lm_msg_ident;
437		arg.cookie.n_len = sizeof(msg->lm_msg_ident);
438		arg.alock.caller_name = hostname;
439		arg.alock.fh.n_bytes = (char *)&msg->lm_fh;
440		arg.alock.fh.n_len = msg->lm_fh_len;
441		arg.alock.oh.n_bytes = (char *)&owner;
442		arg.alock.oh.n_len = sizeof(owner);
443		arg.alock.svid = msg->lm_msg_ident.pid;
444		arg.alock.l_offset = msg->lm_fl.l_start;
445		arg.alock.l_len = msg->lm_fl.l_len;
446
447		if ((cli = get_client(
448		    (struct sockaddr *)&msg->lm_addr,
449		    NLM_VERS)) == NULL)
450			return (1);
451
452		set_auth(cli, &msg->lm_cred);
453		(void)clnt_call(cli, NLM_UNLOCK_MSG,
454		    (xdrproc_t)xdr_nlm_unlockargs, &arg,
455		    (xdrproc_t)xdr_void, &dummy, timeout);
456	}
457
458	return (0);
459}
460
461int
462lock_answer(int pid, netobj *netcookie, int result, int *pid_p, int version)
463{
464	struct lockd_ans ans;
465
466	if (netcookie->n_len != sizeof(ans.la_msg_ident)) {
467		if (pid == -1) {	/* we're screwed */
468			syslog(LOG_ERR, "inedible nlm cookie");
469			return -1;
470		}
471		ans.la_msg_ident.pid = pid;
472		ans.la_msg_ident.msg_seq = -1;
473	} else {
474		memcpy(&ans.la_msg_ident, netcookie->n_bytes,
475		    sizeof(ans.la_msg_ident));
476	}
477
478	if (d_calls)
479		syslog(LOG_DEBUG, "lock answer: pid %lu: %s %d",
480		    (unsigned long)ans.la_msg_ident.pid,
481		    version == NLM_VERS4 ? "nlmv4" : "nlmv3",
482		    result);
483
484	ans.la_set_getlk_pid = 0;
485	if (version == NLM_VERS4)
486		switch (result) {
487		case nlm4_granted:
488			ans.la_errno = 0;
489			break;
490		default:
491			ans.la_errno = EACCES;
492			break;
493		case nlm4_denied:
494			if (pid_p == NULL)
495				ans.la_errno = EAGAIN;
496			else {
497				/* this is an answer to a nlm_test msg */
498				ans.la_set_getlk_pid = 1;
499				ans.la_getlk_pid = *pid_p;
500				ans.la_errno = 0;
501			}
502			break;
503		case nlm4_denied_nolocks:
504			ans.la_errno = EAGAIN;
505			break;
506		case nlm4_blocked:
507			return -1;
508			/* NOTREACHED */
509		case nlm4_denied_grace_period:
510			ans.la_errno = EAGAIN;
511			break;
512		case nlm4_deadlck:
513			ans.la_errno = EDEADLK;
514			break;
515		case nlm4_rofs:
516			ans.la_errno = EROFS;
517			break;
518		case nlm4_stale_fh:
519			ans.la_errno = ESTALE;
520			break;
521		case nlm4_fbig:
522			ans.la_errno = EFBIG;
523			break;
524		case nlm4_failed:
525			ans.la_errno = EACCES;
526			break;
527		}
528	else
529		switch (result) {
530		case nlm_granted:
531			ans.la_errno = 0;
532			break;
533		default:
534			ans.la_errno = EACCES;
535			break;
536		case nlm_denied:
537			if (pid_p == NULL)
538				ans.la_errno = EAGAIN;
539			else {
540				/* this is an answer to a nlm_test msg */
541				ans.la_set_getlk_pid = 1;
542				ans.la_getlk_pid = *pid_p;
543				ans.la_errno = 0;
544			}
545			break;
546		case nlm_denied_nolocks:
547			ans.la_errno = EAGAIN;
548			break;
549		case nlm_blocked:
550			return -1;
551			/* NOTREACHED */
552		case nlm_denied_grace_period:
553			ans.la_errno = EAGAIN;
554			break;
555		case nlm_deadlck:
556			ans.la_errno = EDEADLK;
557			break;
558		}
559
560	if (nfslockdans(LOCKD_ANS_VERSION, &ans)) {
561		syslog(((errno == EPIPE || errno == ESRCH) ?
562			LOG_INFO : LOG_ERR),
563			"process %lu: %m", (u_long)ans.la_msg_ident.pid);
564		return -1;
565	}
566	return 0;
567}
568
569/*
570 * show --
571 *	Display the contents of a kernel LOCKD_MSG structure.
572 */
573void
574show(LOCKD_MSG *mp)
575{
576	static char hex[] = "0123456789abcdef";
577	struct fid *fidp;
578	fsid_t *fsidp;
579	size_t len;
580	u_int8_t *p, *t, buf[NFS_SMALLFH*3+1];
581
582	syslog(LOG_DEBUG, "process ID: %lu\n", (long)mp->lm_msg_ident.pid);
583
584	fsidp = (fsid_t *)&mp->lm_fh;
585	fidp = (struct fid *)((u_int8_t *)&mp->lm_fh + sizeof(fsid_t));
586
587	for (t = buf, p = (u_int8_t *)mp->lm_fh,
588	    len = mp->lm_fh_len;
589	    len > 0; ++p, --len) {
590		*t++ = '\\';
591		*t++ = hex[(*p & 0xf0) >> 4];
592		*t++ = hex[*p & 0x0f];
593	}
594	*t = '\0';
595
596	syslog(LOG_DEBUG, "fh_len %d, fh %s\n", (int)mp->lm_fh_len, buf);
597
598	/* Show flock structure. */
599	syslog(LOG_DEBUG, "start %qu; len %qu; pid %lu; type %d; whence %d\n",
600	    (unsigned long long)mp->lm_fl.l_start,
601	    (unsigned long long)mp->lm_fl.l_len, (u_long)mp->lm_fl.l_pid,
602	    mp->lm_fl.l_type, mp->lm_fl.l_whence);
603
604	/* Show wait flag. */
605	syslog(LOG_DEBUG, "wait was %s\n", mp->lm_wait ? "set" : "not set");
606}
607